Tesla Wants to Build a Battery for Your House

[Willy T]

Once again only about 10% of whats been posted was actually said in the Video.

Tesla 7 Kwh system will not be available because there is no way to integrate it into a Grid Tied System because state and federal regulations will not allow it to be used as intended for Peak Load shifting.

Thats funny since the Fronius Hybrid Inverter is already being sold with their own battery that does exactly that and was never said in the video. In fact any hybrid Inverter will sell or can use Grid support.

[Sunking]

Tesla is probably using the same batteries as in their cars, but that is not certain.

It is certain, they are using the same batteries that they put in their S models. If you have an half an hour to watch this video with Tesla VP Jim Chin. He tells you you exactly what inside the Powewall's. Same battery used in the S model with different controls to limit discharge and DOD rates to extend cycle life. He also states or admits Tesla 7 Kwh system will not be available because there is no way to integrate it into a Grid Tied System because state and federal regulations will not allow it to be used as intended for Peak Load shifting. Utilities and regulations will not allow a person to buy and store cheap Off-Peak power from the utility, then turn around and sell it at higher price Peak Hours for a profit. That would be stupid. What he admits is the market is utility scale and large commercial users using commercial sized systems. The consumer market is a Hoax.

What it all boils down to is hype on Musk part to get a False bump in stock price which has worked as of now. Great if you have Tesla stock and looking to sell a few shares.

400v isn't a good choice choice for residential retrofit, but that is not the market they are designing for. The unit likely needs to be closing tied to inverter control functions, so the powerwall isn't suitable for a straight battery replacement anyways.

That is explained in the video too. Tesla chose 400 volts because they use the same control equipment they use in their vehicles. They just adapted it to the smaller scale Powerwall. In other words they stuck with what they already have and know. Higher voltage has a lot of merits. But as you pointed out is not used in off grid applications. To make it work requires a DC-to-DC converter or another expensive egg in the basket until someone makes an Inverter to work with it which will be expensive.

[bberry]

Tesla is probably using the same batteries as in their cars, but that is not certain. Even the 18650 form factor isn't certain to be produced by the gigafactory. I've seen speculation that a larger physical cylindrical size is probably more efficient to produce. As they plan the ramp up to massive production they need to question all legacy choices.
400v isn't a good choice choice for residential retrofit, but that is not the market they are designing for. The unit likely needs to be closing tied to inverter control functions, so the powerwall isn't suitable for a straight battery replacement anyways.

When companies come out with a more closed system, like Tesla Energy or Apple, the door is opened for companies to produce products that are more suitable for end user flexibility.

[Sunking]

I know plenty, we're talking about capacity and the 3 kw difference and you go off on cycle life and limiting the discharge rate. Keep on Guessing.

Who is guessing? Tesla clearly states they are the same battery and limit discharge rates and DOD. Anyone who knows anything about batteries knows volume and weight are directly related. You do not know that yet. If you did you would instantly know a 220 pound battery is the same as another identical 220 pound battery.

[Willy T]

OK you do not know anything about batteries. My bad for trying to educate you.

I know plenty, we're talking about capacity and the 3 kw difference and you go off on cycle life and limiting the discharge rate. Keep on Guessing.

[Sunking]

Only you could understand that contorted explanation. More guessing on your part.

OK you do not know anything about batteries. My bad for trying to educate you.

[Willy T]

You cannot get more than 10 Kwh out of it. Why are you having such a hard time with it? To get the daily 7 Kwh Tesla has to restrict both DOD to 70%, and 2 Kwh max discharge rate to get the extra cycle life out of it. It is not that hard to understand. Unless of course you know nothing about batteries.

Only you could understand that contorted explanation. More guessing on your part.

[Sunking]

The 10 kw is restricted to ??

You cannot get more than 10 Kwh out of it. Why are you having such a hard time with it? To get the daily 7 Kwh Tesla has to restrict both DOD to 70%, and 2 Kwh max discharge rate to get the extra cycle life out of it. It is not that hard to understand. Unless of course you know nothing about batteries.

[Sunking]

Speculative (likely an educated guess however given your background) but irrelevant since my statement was a best possible rough guess that still won't pan out. Its not a good deal assuming optimum pricing and zero degradation over time.

No speculation, right from the horses mouth. Solar City is the sole supplier. Go Google this quote:

SolarCity has quoted $7,140 for an outright purchase of the Powerwall

You will get dozens of hits from multiple media outlets quoting Solar City. The $3000 is is completely bogus.

[Willy T]

Just where is the problem? No guesses, just physical facts. The battery is 400 volts @ 24 AH aka 10 Kwh in both models. 7 Kwh is restricted to 70% DOD.

The 10 kw is restricted to ??

[Sunking]

Then why did you say this ?? Maybe your lost or having a bad day remembering anything. looks like the math is your problem. Guessing again.

Just where is the problem? No guesses, just physical facts. The battery is 400 volts @ 24 AH aka 10 Kwh in both models. 7 Kwh is restricted to 70% DOD.

[kwilcox]

You cannot touch it for $3000, that is wholesale price to dealers. $7000 if you want one outright.

Speculative (likely an educated guess however given your background) but irrelevant since my statement was a best possible rough guess that still won't pan out. Its not a good deal assuming optimum pricing and zero degradation over time.

[Willy T]

No that is where you start. Next you look up thee Patent and UL applications.

Tesla is using the same batteries they are using in the S model car. If you know anything about batteries, the most basics of physical properties, is that batteries physical size in volume and weight are directly proportional to the energy capacity contained within them. A 10 Kwh battery is going to be 42% larger and heavier than a 7 Kwh battery. It is simple 5th grade math.

Then why did you say this ?? Maybe your lost or having a bad day remembering anything. looks like the math is your problem. Guessing again.

Only difference between them is the firmware to restrict the DOD. Both are a 400 volt 25 AH battery (10 Kwh). Same cabinet, exact same dimensions, exact same weight, exact same battery, just different firmware in the code that restricts DOD.

[russ]

It is simple 5th grade math.

I expect that these days it may be high school math.

[Sunking]

Based on that data, I concur that it doesn't sound like any kind of deal. Even @ 3K installed,

You cannot touch it for $3000, that is wholesale price to dealers. $7000 if you want one outright.